$A$ ball of mass $0.2 \ kg$ moving with a speed of $20 \ m s^{-1}$ is brought to rest in $0.1 \ s$. The average force applied to the ball is (in $N$)

$A$ soccer ball of mass $250 \text{ g}$ is moving horizontally to the left with a speed $22 \text{ ms}^{-1}$. This ball is kicked towards the right with a velocity $30 \text{ ms}^{-1}$ at an angle $53^{\circ}$ with the horizontal in the upward direction. Assuming that it took $0.01 \text{ s}$ for the collision to take place, the average force acting is $(\cos 53^{\circ} = \frac{3}{5}; \sin 53^{\circ} = \frac{4}{5})$. (in $\text{ N}$)

When the speed of a moving body is doubled:

$A$ machine gun can fire $200$ bullets $\min^{-1}$. If $35 \ g$ bullets are fired at a speed of $750 \ m \ s^{-1}$, the average force exerted by the gun on the bullets is, (in $N$)

In projectile motion,two particles of masses $m_1$ and $m_2$ have velocities $\vec{V}_1$ and $\vec{V}_2$ respectively at time $t=0$. Their velocities become $\vec{V}_1^{\prime}$ and $\vec{V}_2^{\prime}$ at time $2t$ while still moving in air. The value of $[(m_1 \vec{V}_1^{\prime} + m_2 \vec{V}_2^{\prime}) - (m_1 \vec{V}_1 + m_2 \vec{V}_2)]$ is ($g =$ acceleration due to gravity).

Two trains $A$ and $B$ are running in the same direction on parallel rails such that $A$ is faster than $B$. Packets of equal weight are transferred between them. What will happen due to this?